As the global plastic crisis deepens, a new generation of packaging is emerging with a clear message: break down naturally or don’t exist at all. Design and materials company Sway has evolved its compostable plastic bags made from seaweed, offering an alternative to conventional plastic packaging that is designed to return to the soil rather than linger in landfills or oceans for decades.
Unlike traditional plastics that rely on recycling systems often stretched to their limits, these bags are intentionally created for composting. The goal, the company says, is not to recycle plastic endlessly, but to eliminate long-term plastic waste altogether.
Sway’s packaging is made using a blend of seaweed, plant-based materials and compostable polymers. Seaweed, a fast-growing marine resource that does not require freshwater, fertilisers or land cultivation, forms the backbone of the material. Through refined processing techniques, the company has made the bags stronger, more durable and more affordable, while ensuring they last only as long as they are needed.
After use, the bags can be placed in home compost or industrial composting systems, where they gradually break down into nutrient-rich soil. According to the company, they do not leave behind microplastics or toxic residues one of the most persistent problems associated with conventional plastics.
If composting facilities are unavailable, the bags can be disposed of in general waste. While not ideal, Sway maintains that even in this scenario, the material avoids the long-term environmental damage caused by petroleum-based plastics.
The packaging range includes polybags for shipping products, die-cut handle bags for retail and everyday shopping, and flexible film wraps. All versions share a smooth, frosted texture with a translucent finish, allowing the contents to remain visible while maintaining a clean, minimal aesthetic.
The die-cut handle bags are aimed at shops and daily consumers, while the polybags are designed for businesses that require protective yet sustainable shipping solutions. Sway says recent improvements mean the bags can carry heavier loads without compromising their compostable nature.
In early 2026, the company announced that changes in processing had made the material stronger and visually refined, while also enabling production at higher volumes and lower costs key factors for wider adoption by businesses.
A notable aspect of Sway’s approach is its firm stance that the bags are not meant to be recycled. The company argues that recycling systems are often inefficient, with large volumes of plastic still ending up in landfills or the natural environment. By designing packaging specifically for composting, the aim is to close the loop in a more reliable way.
Several versions of the packaging have already received industrial compost certification from international certification bodies, while home compost certification for newer variants is currently in progress. Distribution partnerships with packaging suppliers have helped bring the product to businesses, small markets and shipping operations.
As governments and consumers push for alternatives to single-use plastics, seaweed-based materials are gaining attention as a viable solution. Sway’s compostable bags highlight a broader shift in design philosophy one that prioritises materials capable of reintegrating into natural systems rather than persisting as waste.
While challenges remain, including access to composting infrastructure, the development signals a move toward packaging that aligns more closely with environmental cycles. In a world overwhelmed by plastic, these seaweed-based bags suggest that the future of packaging may lie not in recycling more, but in designing waste that can disappear responsibly.